小编ivk*_*knv的帖子

问题在于Polygon::FindAxisLeastPenetration:

double Polygon::FindAxisLeastPenetration(unsigned int *faceIndex, const Polygon &polygonA, const Polygon &polygonB) const {
  double bestDistance = -std::numeric_limits<double>::infinity();
  unsigned int bestIndex;

  for (unsigned int i = 0; i < polygonA.points.size(); i++) {
    Vector2D n = polygonA.normals[i];
    Vector2D nw = polygonA.rotationMatrix * n; //ROTATION
    Matrix22 buT = polygonB.rotationMatrix.Transposed();
    n = buT * nw; //ROTATION

    Vector2D support = polygonB.points[polygonB.GetSupport(-n)];

    Vector2D vertex = polygonA.points[i];
    vertex = polygonA.rotationMatrix * vertex; //ROTATION
    vertex.Add(polygonA.body->GetPosition());
    vertex.Subtract(polygonB.body->GetPosition());
    vertex = buT * vertex; // ROTATION
    double distance = …

我使用JSON简单来解析JSON,并NoClassDefFoundError在尝试创建JSONParser对象时得到.

import org.json.simple.JSONObject;
import org.json.simple.JSONArray;
import org.json.simple.parser.JSONParser;
...
JSONParser parser = new JSONParser();

我用命令编译程序:

javac MyProgram.java -cp json-simple-1.1.1.jar

它编译得很好.但是当我用这个命令执行程序时:

java MyProgram

我明白了 NoClassDefFoundError

我究竟做错了什么？

编辑:
完整错误:

Exception in thread "main" java.lang.NoClassDefFoundError: org/json/simple/parser/JSONParser
        at getNotesFromNoter.sendPost(getNotesFromNoter.java:53)
        at getNotesFromNoter.main(getNotesFromNoter.java:14)
Caused by: java.lang.ClassNotFoundException: org.json.simple.parser.JSONParser
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.net.URLClassLoader$1.run(Unknown Source)
        at java.security.AccessController.doPrivileged(Native Method)
        at java.net.URLClassLoader.findClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
        at java.lang.ClassLoader.loadClass(Unknown Source)
        ... 2 more

我有这个代码:

class Vector2D(object):
    def __init__(self, x=0.0, y=0.0):
        self.x, self.y = x, y

    def rotate(self, angle):
        angle = math.radians(angle)
        sin = math.sin(angle)
        cos = math.cos(angle)
        x = self.x
        y = self.y
        self.x = x * cos - y * sin
        self.y = x * sin + y * cos

    def __repr__(self):
        return '<Vector2D x={0}, y={1}>'.format(self.x, self.y)

class Polygon(object):
    def __init__(self, points):
        self.points = [Vector2D(*point) for point in points]

    def rotate(self, angle):
        for point in self.points:
            point.rotate(angle)

    def center(self):
        totalX = totalY …